1. Field of the Invention
The present invention generally relates to a heat dissipation element and an illumination device. More particularly, the present invention relates to a heat sink and a light emitting diode (LED) lamp having high heat dissipation efficiency.
2. Description of Related Art
LEDs are semiconductor devices. The light emitting chips are mainly made of a compound semiconductor material containing III-V group chemical elements, for example, GaP, GaAs, and the like, and function on the principle of converting electric energy to light. That is to say, the compound semiconductor is powered to release excessive energy through the combination of electrons and holes, so as to emit photon (light). The LED can emit light without being heated or does not discharge to emit light. Therefore, the lifespan of the LED is up to 100,000 hours, and an idling time is not required. In addition, the LED has advantages of quick response speed (approximately 10−9 seconds), small volume, power-saving, low pollution, high reliability, and ease mass production. Thus, the LEDs have been intensively used in many fields, for example, light source and illumination device in large-scale bulletin boards, traffic lights, cellular phones, scanners, fax machines, etc.
Currently, the light emitting brightness and efficiency of the LEDs are continuously improved, and meanwhile the white LEDs with high brightness are successfully put into mass production, so the white LEDs have been gradually used in illumination devices such as indoor illumination and outdoor street lamp. Generally, heat dissipation performance is important to high power LEDs. If LEDs operates under high temperature, the brightness that the LED light can provide may be reduced and the life span thereof is reduced. Therefore, how to enhance heat dissipation performance of LEDs is an important topic for research and development people.
Currently, the heat dissipation element of the LEDs is made of aluminium by extrusion, and this method will cause material waste since the remaining aluminium after extruding is discarded. Namely, the remaining aluminium has fallen into disuse. In addition, materials that can be used in this method are limited to materials which have good extension capability.